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2011/01/08

J-20

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The new Chinese J-20 fighter prototype has been unveiled (unofficially) and was photographed and filmed a lot in the past days.

We already saw that the Russian developers of the PAK-FA / T-50 appeared to place a greater emphasis on agility than the U.S. F-22, and the J-20's developers seem to have done the same. The signs are a bit more subtle this time (the T-50 almost looked like a good old Russian 80's aerobatics fighter):

The fins below the tail (good for high angle of attack - only necessary while manoeuvring), the turbofan nozzles (apparently thrust vectoring in one more dimension than the F-22's) and the canards both point at a more agile fighter.

The sheer size on the other hand points at a large internal fuel volume (possibly also a large internal weapons bay) with correspondingly great range.

The latter reduces the necessity of tanker aircraft, which should be taken into account as reducing the overall cost of an air force. A good range also helps a lot to overcome operational problems and reduces the potential for friction (such as suddenly unavailable tankers).

The overall appearance suggests that the J-20 is meant to be at least a low-observable (LO) combat aircraft ("fighter" is just an assumption), probably even meant to be less detectable than the T-50 (you cannot read everything from the shaping, but it really seems to point at frontal VLO and LO to the sides).

I suspect that this aircraft will become operational in significant quantity rather late in this decade.

The good news: It's most likely no problem for Europeans, as long as they don't meddle in East Asian affairs.

19 comments:

"The fins below the tail (good for high angle of attack - only necessary while manoeuvring), the turbofan nozzles (apparently thrust vectoring in one more dimension than the F-22's) and the canards both point at a more agile fighter."

More agile than what? A DC-3? That sucker is huge. Thrust vectoring or no, if it gets bounced by an F-16 or a Rafale . . .

Sheer size is nowadays a poor indicator for agility. This has been proved by the Su-27/T-10 family.

The much smaller F-35 isn't even rated for high agility, for example. A F-16 represents top late 70's agility, which is a league below the Typhoon's top 80's technology agility.

Thrust vectoring is a huge factor as well, especially if the opposing aircraft has no significant thrust/weight advantage.

Besides; agility is nowadays probably not important against fighters, but against (their) missiles. Agility comparisons should be done for evasive manoeuvres against the engagement envelope of an incoming missile instead of in dogfighting terms.

Helmet-mounted sights and high off-boresight sensor AAMs have pretty much killed dogfighting.

You're more up on this than I, you say that big barge will be more agile than an F-22, OK. Shows what I know. And you're right about the missiles. But, war has its surprises, and sometimes that super aircraft will get caught in the wrong space at the wrong time. Maybe the avionics blipped and didn't see a bogie, or the pilot didn't see it. However, considering that the G-loading on the pilot is now the limiting factor and has been for decades, maybe the old stuff could be useful for a while yet. Like Nowotny found, ya gotta land sometime.

And jeez, that sure looks like one big barge of a "fighter". Looks bigger than an old F-111.

First big "NO!":Fins below the tail are for roll-stability over the total range of angles of attack flyable as long as designers have not mastered the interaction of aerodynamics and digital flight control. That's why MiG-29, Su-27 and F-16 need them but MiG-35, Su-34/35, Pak-Fa and F-22 don't. But they do not make the aircraft flying higher angles of attack and therefore do not point to higher agility! Canards dito, as there main function is nick-stability of tailless delta-designs. Higher agility is merely a side effect. Second big "NO!":While it is true, that you cannot read everything from shaping with regard to stealthiness, you can read from it abundantly more with regard to stealthiness than to agility. Because shaping makes for the first 100 to 1000-fold reduction of RCS while materials make for the remaining 1 to 10-fold reduction. Now I could make a big story about why taking more emphasis on kinematics gives you a design superior to ones with stealthiness as their primary design objective. The simple truth is that incremental advances in stealth technology get smaller and smaller while those of radar technology to counter stealth get bigger and bigger! A quick look at the Nebo-SV family of air surveillance radars will tell you why!to be followed...

To assess agility of a fighter design needs a lot more than looking at its shape! Here we need realistic but so far secret technical figures like empty weight, dry thrust of the engine, wing area, wing loading etc. etc. But more important: What rules in dogfight is maneuverability and less agility. In my use of the term agility means rate of rolling, nicking and yawing, leading to a change of attitude of the aircraft in relation to the airflow but not a change of direction of movement. Maneuverability, on the opposite, is defined by rate of turning at a certain speed and altitude. It is therefore a product of turning speed and radius. Wing loading is here the one important figure to be known. In turning, relative attitude of the aircraft never changes but the direction of its movement changes constantly.Those who state the end of dogfights are wrong! to be continued...

Those fins are still fully effective at high AoA, while the small normal vertical tails aren't. A high AoA is important for turning rate and a design emphasis on it at the expense of problems with VLO points at an emphasis on agility imo.

Canards are problematic in several regards, including VLO considerations - and more so than normal horizontal stabilisers. Again, this looks like a compromise that emphasised agility more than the F-22 design did.

While it's of course impossible to guess the actual dogfighting or missile evasion ability of an aircraft just by the looks, it IS possible to recognize features that point towards this or that emphasis.

A 360° vision canopy as on F-15/F-16 points at the developer's concern about dogfighting (and avoiding being surprised), for example. The shaping of the J-20 points at a LO or VLO requirement. The nozzle layout (if it's anything like final) points at no rear sector VLO requirement...

Ok, let's come to the crux of the matter. And let us forget what points toward this or that but let us define what actually makes a good dogfighter! What makes F-16, MiG-29 and Su-27 high maneuverability fighters is comparable low wing loading for 70's technology combined with high thrust-to-weight ratios. How to gain low wing loading? By increasing lift! How to increase lift? By making the body, while consuming lift due to its weight, supporting lift by the application of LERX and therefore an integrated body-wing-design. By comparing our 3 competitors shape, only the PaK-Fa has a superior design - kinematically superior to both, F-22 and J-20. Neither the F-22 nor the J-20 employ aerodynamically integrated design features. While the J-20 obviously tries to exploit high maneuverability of the delta-canard design you cannot conclude a superiority over the F-22 - no matter what points to this or that! (I deny talking about the JSF. "Piece of crap" expresses politeness toward it. Whatever designers can default on developing an aircraft it happened with the JSF!)to be followed ... :-)

Missile kinematics is a bit tricky. Long range AAM's are traditionally the most unreliable missiles with regard to sensor effectiveness and kinematics. They are easy to avoid even for less sophisticated fighters. (Given you have early warning!) Short range AAM's nowadays became really deadly. A russian R-74 pulls 90g and is therefore kinematically more or less undefeatable! Here, investment in the defeat of its sensors make far more sense. (By the way, the russians have already solved both problems and will be years ahead of MBDA's Meteor missile if it will ever enter service!)Conclusion for the J-20:Optimised front aspect stealth, big internal volume for fuel and weapons and an abashing try to get some agility out of if makes it possible to break through US carriers radar fences up to the "second chain of islands" and therefore broadens chinas regional hegemony. Air combat (With no numerical advantage for any side!) with F-22 remains an open question as long as there become more technical data available for both. Pak-Fa, once fully developed, surpasses both in BVR and WVR combat and even more so as there is support from S-300/400, Nebo-SV family of radars and the new C4 capable A-50M.

Go ahead with your great work, Sven! I admire it grossly!Many Thanks for this site.zoni

I think we see here probably not the last, but one of the biggest nails in the coffin of the F-35. The T-50 already was an indicator, the J-20 will probably have a more profound impact, not just the aircraft itself, but the technologies and Chinas industrial capabilities, regardless of wether the T-50 is a better aircraft.

Timeframe-wise I am not a cheerleader for the Chinese, but even so a LRIP run around 2015/16 and FRP about two years later seem to be realistic, based on past developments and the J-10 in particular. The Indians will be hard-pressed to get their act together with the PAKFA-co-operation

As far as numbers are concerned, it will be interesting to see, if the J-10B was indeed just a testbed for the J-20 or if it will be put in mass-production (and wether J-10B-capabilities are cost effective).

Exactly!! The single most critical decision was to end production of the F-22 at 180+ since from the very first day it was meant to be the bodyguard for the JSF. All Air Forces planning to operate the JSF without the presence of a modern air superiority fighter should be questioned for their mental health. Especially the Europeans, who don't have either. They neither have ground attack nor air superiority fighters capable of surviving a modern Russian equipped IADS. When I visit western aviation forums the general mood is like this: the Chinese can be lucky to have 10-12 J-20 in the 2025 time frame. And even than their true capabilities are at least questionable. This is what neurologists refer to as cognitive dissonance. Both, China and Russia, will field aircrafts with better than F-22 characteristics in nearly F-35 numbers. So long, western world!

Me thinks the JSF's primary purpose was to kill the Euro mil aviation business and keep the allies on a tight leash. Had it not been for the B variant dragging the whole thing down, it might have just worked.

The Russians simply don't have enough modern air defence assets to pose a problem, nor do they export enough of them.

It took combined efforts to establish a 1,000 km long line of area air defence systems in germany during the Cold War, and even back then many rather old systems were involved. Standard M2 fighters were able to fly high & fast over IHawk areas, for example.

A modern conflict would involve less air defences on likely a larger or similarly large front.

The use of ALCMs like Taurus, Apache, Storm Shadow and the availability of long-range artillery such as 80+ km GMLRS helps a lot even against the best air defences as well.

Finally, air defences were historically not so much about killing as about denying airspace or serving as one component of combined arms air war. The rise of BVR combat (quite the same as area AD) might have changed that, of course.

Now a bit more general: You don't win a war by defence alone. The Russians are apparently still inferior in regard to strike packages, so thier possible defensive strength may be matched by their likely offensive weakness.

In the end, this might point at what I've been writing several times: Air war is likely not going to decide land war campaigns or obliterate enemy forces. It's rarely more than mere support to the really decisive land forces operations.

Agreed! But: The single biggest mistake military analysts can do is to look at the now and here instead of the then and there! Economic indicators do not point toward a western advantage over the coming decade. Nowhere in the world you get less for a taxpayers Dollar with regard to military capability than in Europe and the US. Western Armed Forces are only there to serve profit driven interests of Share Holders and lobbied politicians. Getting billions of Dollars and delivering next to nothing!A couple of days before Almaz-Antey got credit for investment in another two factories producing air defense assets to meet domestic and foreign demand. Have you ever wondered what makes the difference between a BUK-M1E and a BUK-M2E or what is the idea behind the Pantsir-S1 or behind the Nebo-M radar system?? Their single most important mission, they are optimized for, is to defeat any kind of PGM's to protect strategic air defense assets. And again: European military planners should be questioned over their mental health for dumping billions of taxpayers money in ineffective systems like Storm Shadow, Taurus or Apache. Those arrogant and self applauding NATO-generals were not even able to break through a 60's era IADS of the Serbs with their best technologies and overwhelming numbers. Nearly all of the air and sea launched CM's were downed and/or their sensors defeated by rather cheap teasers on the ground. Success of a stand-off weapon is closely correlated to its speed! While nearly all western ALCM's, CM's and PGM's are subsonic and therefore highly vulnerable, Russian Sunburns, Yakhonts, Brahmos, Sizzlers, Iskanders and Kryptons kill us at supersonic speeds. Some of them even with Mach 2.8! But the best is your reference to high precision artillery! Isn't it the Russians who first produced a laser guided artillery round! French artillery is completely equipped with the Krasnodar-projectile. The Americans just killed their FCS because of inability to make their precision round work. And when it comes to strike packages I would be very careful in my assumptions. A Typhoon is a far cry of a Su-34 which just started to arrive in the inventory of the Russian Air Force!Time will tell!

zoniman; NATO broke through Yugoslav air defences without casualties, they just failed to knock them out permanently.

The first guided artillery round was afaik Copperhead, a U.S. product.

The difference between subsonic and supersonic cruise missiles is also the cruise and terminal attack altitude. Supersonic missiles can't fly as low as subsonic ones (<6 m over water, <30 m over land).Some cruise missiles and drones were shot down by Yugoslav air defences (by VShorAD mostly) afaik, but I've yet to see a source that "nearly all" were countered successfully.

The bombing of mobile targets was such a failure with lots of decoys hit and terrible BDA, though.

Yes, I totally agree! Please apologize! When it comes to that conflict I get bit emotional and populist. I should express myself more exactly! The term "nearly all" refers to those missiles, which actually came into firing range of an air defense asset capable of engaging it. KUB's did rather well as I've heard! But look at this:

http://www.youtube.com/watch?v=QdeTsjWFAYI

Numbers here got lateral confirmation from more than one web source. Nonetheless, they are incomplete as they only refer to those losses coming down within the borders of Yugoslavia.

But this is not about Yugoslavia. It is about the J-20. MAIDEN FLIGHT today!